1. Field of the Invention
This invention relates to an article with transient infrared radiation response characteristics, having utility as an electronic warfare countermeasure, e.g., for anti-detection masking of an offensive attack. The invention also relates to an appertaining method of use of such article, to mask an infrared radiation response when deployed in an area susceptible to infrared radiation monitoring.
2. Description of the Related Art
In modem warfare, a wide variety of weapons systems are employed which operate across the electromagnetic spectrum, including radio waves, microwaves, infrared signals, ultraviolet signals, x-rays and gamma rays.
Infrared countermeasures therefore are becoming of greater importance to the U.S. military, particularly in the context of proliferation of heat-seeking missiles and infrared guided arms in military arsenals. Infrared countermeasures fall into two primary groups: decoys and smokes.
Infrared decoys typically take the form of flares or active metal compositions which in use yield a thermal response simulating the thermal signature of an endangered target for some predetermined period of time.
Infrared smoke can be constituted by warm clouds of gases or clouds of attenuating particles. Both graphite flake and brass flake materials have been employed as smoke-forming materials which obscure infrared targets for military operations. This obscuration is accomplished by absorption and/or diffuse scattering of the incident infrared radiation. Fixed and slow moving "assets" can thus be protected by deploying a `smoke` cloud between the asset and the threat. Unfortunately, the properties of previously demonstrated graphite and brass infrared radiation obscuration materials remain unchanged and these materials persist indefinitely in the environment. Although the enemy cannot see beyond the infrared-obscuring cloud, neither can friendly forces, thus rendering the friendly force weaponry and monitoring equipment correspondingly useless.
In addition to such deficiency of graphitic or brass flake smoke materials, brass is toxic in character, while both graphite and brass have very stable electrical conductivity and thus can affect the environment in which they are deployed for long periods of time.
Accordingly, there is a need in the art for an infrared radiation countermeasure, which is able to be deployed readily to provide a transient infrared radiation response characteristic, which is non-toxic in character, and which is environmentally benign.
It therefore is an object of the present invention to provide an infrared radiation countermeasure of such type, having superior infrared radiation signature characteristics.
It is another object of the invention to provide a method of providing a transient infrared radiation reflectance signature, having utility in the obscuration of tactical and strategic military assets in warfare field operations.
Other objects and advantages of the present invention will be more fully apparent from the ensuing disclosure and appended claims.